if you tie up the frame you can get them to stop bleeding. But if you have horsepower they will always have a drip.best fix i used was feeding a rope through the rubbers.with lots of playing with the adjusters.
I had one for 15 years. The 78 to 81 tops are ok but will always have a little drip when it rains. The 76 and 77 ones are terrible. My advice...If you can get a hard top, its one more thing you dont have to work on. My next car, when I find it will only be a hard top car with SQUARE shaped door glass. Metro weather seals are the best ones for a resto if you need them replaced. I have plenty of nightmare stories about restoring a project car with t-tops...